A special coating laser etching process method based on CO2 laser

Abstract

The application discloses a kind of based on CO2 laser's special coating laser etching process method, and CO2 laser is used to the laser etching processing of medium temperature radar stealth coating, and the whole solid phase of material is etched by the action of heat-induced stress, and the etching processing of micro groove can slow down the internal stress of hard and brittle coating in high temperature service process, and reduce the tendency of coating peeling and cracking.The technical key of process method: one is etching area design, including groove width, groove depth and etching area selection;Two is to use CO2 laser as light source, select appropriate process parameters, so that the whole solid phase of material is etched, and metal element melting is avoided.The application has the advantages that: solve the micro groove processing problem of medium temperature radar stealth coating surface, solve the problem of metal element melting caused by traditional laser etching process, improve the service life of component with stealth coating, realize the development of aviation engine special stealth coating laser surface etching from scratch.

Description

TECHNICAL FIELD

[0001] The application relates to a laser etching process method for a medium-temperature radar stealth coating of an aero-engine and belongs to the technical field of aero-engines. BACKGROUND

[0002] The medium-temperature radar wave-absorbing coating of an aero-engine is generally a three-dimensional curved surface structure, is uniformly coated on the surface of a titanium alloy at a thickness of about 0.6 mm, presents a hard and brittle characteristic, and is composed of organic macromolecules and metal elements. In a high-temperature service environment, the coating is prone to peeling and cracking due to the mismatch of thermal stress between the metal base and the coating. Therefore, stress should be released in advance by means of pre-prepared micro-slots to avoid cracking.

[0003] The medium-temperature radar wave-absorbing coating is composed of organic macromolecules and metal elements. The physical properties of the material itself result in a large difference in feedback after laser irradiation. The previous test shows that the absorption rate of organic silicon to long-wavelength laser is high, and the material is more conducive to removal. If the surface is irradiated by conventional infrared laser, ablation and damage are easily caused. Under a suitable process, the CO2 laser processing system can realize the etching and removal of organic silicon and metal elements in the coating at the same time, and the damage to the metal substrate is small. The auxiliary double-pivot laser processing head is more suitable for the removal of organic macromolecular materials on the surface of a three-dimensional complex metal curved surface. SUMMARY

[0004] The application aims to improve the service life of a component with a stealth coating, and provides a special coating laser etching process method based on a CO2 laser.

[0005] The application provides a special coating laser etching process method based on a CO2 laser, characterized in that: a CO2 laser is used for laser etching and processing of a medium-temperature radar stealth coating, the whole material is etched and removed in a solid phase by means of thermal stress, and the etching and processing of the micro-slot can slow down the internal stress of the hard and brittle coating in the high-temperature service process and reduce the peeling and cracking tendency of the coating.

[0006] The stealth coating laser etching technology features:

[0007] The laser etching microstructure is designed by finite element simulation, and the microstructure size and processing position are simulated and designed based on the service temperature.

[0008] The medium-temperature radar stealth coating is composed of organic materials and metal elements. In order to avoid metal melting and blocking the slot, the light force is used. After the laser irradiates the material, a temperature gradient is generated, a gradient distribution internal stress is generated, and the whole solid phase is etched and removed at the interface where the stress difference is greater than the material fracture strength.

[0009] The method comprises the following steps:

[0010] Etching structure design: thermal coupling simulation is carried out through Comsol finite element simulation software, and based on temperature field loading and part characteristics, etching area and processing size are determined;

[0011] Laser process parameter determination: by adjusting laser power, repetition frequency, scanning speed, defocusing amount and other parameters, orthogonal process test is carried out, and etching effect is comprehensively evaluated from etching precision and substrate damage, and process parameters with quality and efficiency are selected;

[0012] According to the part and test, the main process parameter range is determined:

[0013] Laser power: 2~15W;

[0014] Spot shape: circular;

[0015] Laser incidence angle θ: 0~45°;

[0016] Spot size: 0.1mm;

[0017] Overlap rate: 30%~90%.

[0018] Trajectory planning: etching trajectory and path are designed according to part characteristics, and periodic symmetric etching mode is adopted to meet the deformation suppression requirement of thin-walled component laser etching.

[0019] Technical key of process method:

[0020] First, etching area design, including groove width, groove depth and etching area selection;

[0021] Second, CO2 laser is used as light source, and appropriate process parameters are selected to make the material undergo overall solid phase etching, so as to avoid metal element melting.

[0022] It can be applied to the field of stealth coating surface processing of aero-engine, and is suitable for organic and metal mixed coating system. At present, the process method can slow down the cracking tendency of the coating in service and improve the service life of the stealth coating under the condition of low damage and high precision etching. Therefore, the technology has broad application prospect.

[0023] Compared with the prior art, the advantages of the present application are:

[0024] The special coating laser etching process method based on CO2 laser of the present application solves the problem of microgroove processing on the surface of medium temperature radar stealth coating, proposes a whole solid phase etching method of stealth coating based on CO2 laser, solves the problem of metal element melting and slot blocking caused by traditional laser etching process, improves the service life of the component with stealth coating, and realizes the development of laser surface etching of special stealth coating of aero-engine from scratch. BRIEF DESCRIPTION OF DRAWINGS

[0025] The application will be further explained in detail below in conjunction with the accompanying drawings and embodiments:

[0026] Figure 1 Laser etching process principle method of organic matter and metal element hybrid coating

[0027] Figure 2 Photo of material overall etching after CO2 laser etching

[0028] Figure 3 Photo of metal melting and ablation slot after YAG laser etching. DETAILED DESCRIPTION

[0029] The application will be further explained in detail below in conjunction with the accompanying drawings and embodiments:

[0030] Embodiment 1

[0031] The application provides a special coating laser etching process method based on a CO2 laser, characterized in that: a CO2 laser is used to perform laser etching processing on a medium temperature radar stealth coating, and through the action of thermal stress, the material is overall solid-phase etched, and the etching processing of the micro slot can slow down the internal stress of the hard and brittle coating during high temperature service, and reduce the tendency of coating peeling and cracking.

[0032] The laser etching technology of the stealth coating is characterized by:

[0033] The laser etching microstructure is designed by finite element simulation, and the microstructure size and processing position are simulated and designed based on the service temperature.

[0034] The medium temperature radar stealth coating is composed of organic matter and metal elements, in order to avoid metal melting and blocking the slot, the light force is used, the temperature gradient is generated after the laser irradiates the material, the gradient distribution internal stress is generated, and the overall solid-phase etching occurs at the interface where the stress difference is greater than the material fracture strength.

[0035] The method comprises the following steps:

[0036] Etching structure design: thermal coupling simulation is performed through Comsol finite element simulation software, and based on temperature field loading and part characteristics, the etching area and processing size are determined.

[0037] Laser process parameter determination: by adjusting the laser power, repetition frequency, scanning speed, defocusing amount and other parameters, orthogonal process test is carried out, and the etching effect is comprehensively evaluated from etching precision and substrate damage, and the process parameters with quality and efficiency are selected;

[0038] According to the parts and tests, the main process parameter range is determined:

[0039] Laser power: 2W;

[0040] Spot shape: circular;

[0041] Laser incidence angle θ: 0°;

[0042] Spot size: 0.1mm;

[0043] Overlap rate: 30%.

[0044] Trajectory planning: the etching trajectory and path are designed according to the characteristics of the parts, and the periodic symmetric etching mode is adopted to meet the deformation suppression requirement of laser etching of thin-walled components.

[0045] Technical key of process method:

[0046] First, the etching area design, including groove width, groove depth and etching area selection;

[0047] Second, CO2 laser is used as the light source, and appropriate process parameters are selected to make the material undergo overall solid phase etching, so as to avoid metal element melting.

[0048] It can be applied to the field of surface processing of stealth coating of aero-engine, and is suitable for organic and metal mixed coating system. The process method can currently slow down the cracking tendency of the coating in service and improve the service life of the stealth coating under the condition of low damage and high precision etching. Therefore, the technology has broad application prospect.

[0049] The special coating laser etching process method based on the CO2 laser solves the problem of microgroove processing on the surface of the medium temperature radar stealth coating, proposes a whole solid phase etching method of the stealth coating based on the CO2 laser, solves the problem of metal element melting caused by traditional laser etching process, and improves the service life of the component with the stealth coating.

[0050] Example 2

[0051] The application provides a special coating laser etching process method based on a CO2 laser, characterized in that: a CO2 laser is used for laser etching processing of a medium temperature radar stealth coating, the material is etched as a whole by means of thermal stress, and the etching processing of the microgroove can slow down the internal stress of the hard and brittle coating in the high temperature service process, and reduce the peeling and cracking tendency of the coating.

[0052] The stealth coating laser etching technology features:

[0053] The laser etching microstructure is designed by finite element simulation, and the microstructure size and processing position are designed based on service temperature simulation;

[0054] The medium temperature radar stealth coating is composed of organic matter and metal elements. In order to avoid metal melting and blocking the groove, the light force is used. After laser irradiation of the material, temperature gradient is generated, and gradient distribution internal stress is generated. When the stress difference is greater than the material fracture strength, the whole solid phase etching occurs;

[0055] It includes the following steps:

[0056] Etching structure design: thermal coupling simulation is carried out by Comsol finite element simulation software, and based on temperature field loading and part characteristics, etching area and processing size are determined;

[0057] Determination of laser process parameters: by adjusting laser power, repetition frequency, scanning speed, defocusing amount and other parameters, orthogonal process test is carried out, etching effect is evaluated from etching precision and substrate damage, and process parameters with quality and efficiency are selected;

[0058] According to the part and test, the main process parameter range is determined:

[0059] Laser power: 10W;

[0060] Spot shape: circular;

[0061] Laser incidence angle θ: 30°;

[0062] Spot size: 0.1mm;

[0063] Overlap rate: 60%.

[0064] Trajectory planning: etching trajectory and path are designed according to part characteristics, and periodic etching method is adopted to meet the deformation suppression demand of thin-walled components laser etching.

[0065] The technical key of the process method:

[0066] First, etching area design, including groove width, groove depth and etching area selection;

[0067] Second, CO2 laser is used as light source, and appropriate process parameters are selected to make the material etch as a whole, so as to avoid metal element melting.

[0068] It can be applied to the field of stealth coating surface processing of an aero-engine, and is suitable for an organic and metal mixed coating system. The process method can currently ensure low damage and high precision etching, slow down the cracking tendency of the coating in service, and improve the service life of the stealth coating. Therefore, the technology has a wide application prospect.

[0069] The special coating laser etching process method based on the CO2 laser solves the problem of surface micro-groove processing of a medium temperature radar stealth coating, and proposes a whole solid phase etching method of the stealth coating based on the CO2 laser, solves the problem of metal element melting and blocking caused by the traditional laser etching process, and improves the service life of the component with the stealth coating.

[0070] Example 3

[0071] The application provides a special coating laser etching process method based on a CO2 laser, characterized by: the CO2 laser is used for laser etching processing of a medium temperature radar stealth coating, the whole solid phase etching of the material is realized through the action of thermal stress, and the etching processing of the micro-groove can slow down the internal stress of the hard and brittle coating in the high temperature service process, and reduce the peeling and cracking tendency of the coating.

[0072] The stealth coating laser etching technology features:

[0073] The laser etching microstructure is designed by finite element simulation, and the microstructure size and processing position are simulated and designed based on the service temperature;

[0074] The medium temperature radar stealth coating is composed of organic matter and metal elements, in order to avoid the melting and blocking of the metal, the light force is used, the temperature gradient is generated after the laser irradiation of the material, the gradient distribution internal stress is generated, the whole solid phase etching occurs at the interface where the stress difference is greater than the material fracture strength;

[0075] The method comprises the following steps:

[0076] Etching structure design: thermal force coupling simulation is performed through Comsol finite element simulation software, the etching area and processing size are determined based on the temperature field loading and part characteristics;

[0077] Laser process parameter determination: by adjusting the laser power, repetition frequency, scanning speed, defocusing amount and other parameters, orthogonal process test is carried out, the etching effect is comprehensively evaluated from the etching precision and substrate damage, and the process parameters with quality and efficiency are selected;

[0078] According to the part and test, the main process parameter range is determined:

[0079] Laser power: 15W;

[0080] Spot shape: circular;

[0081] Laser incidence angle theta: 45 degrees;

[0082] Spot size: 0.1mm;

[0083] Overlap rate: 90%.

[0084] Trajectory planning: design etching trajectory and path for part features, adopt periodic symmetric etching mode to meet the demand of laser etching deformation inhibition of thin-walled components.

[0085] Technical key of process method:

[0086] First, etching area design, including groove width, groove depth and etching area selection;

[0087] Second, adopt CO2 laser as light source, select appropriate process parameters, so that the material undergoes overall solid phase etching, avoiding metal element melting.

[0088] It can be applied to the field of stealth coating surface processing of aero-engine, and is suitable for organic and metal mixed coating system. The process method can currently ensure low damage and high precision etching, slow down the cracking tendency of the coating in service, and improve the service life of the stealth coating. Therefore, the technology has broad application prospect.

[0089] The problem of micro-groove processing on the surface of medium temperature radar stealth coating is solved, a whole solid phase etching method of stealth coating based on CO2 laser is proposed, the problem of metal element melting and blocking groove caused by traditional laser etching process is solved, and the service life of the component with stealth coating is improved.

[0090] The remaining matters of the present application are well-known technologies.

[0091] Although the embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made thereto without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for laser engraving of special coatings based on CO2 laser, characterized in that: The surface of the medium temperature radar stealth coating is processed by micro-groove laser etching with CO2 laser, which makes the material erode in solid phase by thermal stress, and the etching of micro-groove can reduce the internal stress of hard and brittle coating during high temperature service, and reduce the tendency of coating peeling and cracking. Etching structure design: thermal-mechanical coupling simulation is carried out by finite element simulation software, and the etching area and processing size are determined based on temperature field loading and part characteristics. The medium temperature radar stealth coating is composed of organic matter and metal elements. In order to avoid the blockage of the groove by metal melting, the light force is used to generate temperature gradient and gradient distribution of internal stress after laser irradiation of the material. The whole solid phase etching occurs at the interface where the stress difference is greater than the material fracture strength. Laser process parameter determination: by adjusting the laser power, repetition frequency, scanning speed and defocusing amount, orthogonal process test is carried out, and the etching effect is evaluated comprehensively from etching precision and substrate damage, and the process parameters with quality and efficiency are selected. According to the part and test, the process parameter range is determined: Laser power: 2~15W; Spot shape: circular; Laser incidence angle θ: 0~45°; Spot size: 0.1mm; Overlap rate: 30%~90%.

2. The method of laser etching of special coatings based on CO2 laser as claimed in claim 1, characterized in that: Trajectory planning: the etching trajectory and path are designed according to the part characteristics, and the periodic symmetric etching method is adopted to meet the deformation suppression requirement of laser etching of thin-walled components.

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